Triphenylphosphine → 4-(Benzoylthiomethyl)-1-methylpyrazole

Participants

Reaction Steps

Under nitrogen atmosphere, 78.7 g of triphenylphosphine (300 m mol) and 47.2 ml of diethyl azodicarboxylate (300 m mol) were added to a stirred solution of 22.4 g of 4-hydroxymethyl-1-methylpyrazole (200 m mol) in THF (250 ml) at 5° C. After stirring for 1 hour at the same temperature, 42.3 ml of thiobenzoic acid (360 m mol) was added slowly to the mixture. The mixture was poured into a mixture of water and ethyl acetate, while Ph was adjusted to 9.5 with 30% potassium bicarbonate. Aqueous layer was separated, the organic layer was washed with brine, dried over magnesium sulfate. After filtration of the mixture, the filtrate was concentrated in vacuo, and the residue was purified on silica gel (eluent: n-hexane-ethyl acetate) to afford 4-(benzoylthiomethyl)-1-methylpyrazole (18.3 g).

Provenance & Evidence